Intro
High blood pressure, cholesterol, and bodyweight are responsible for a large and increasing proportion of the global burden of disease. Although historically these risks have been regarded as "Western," their impact is now recognized as global: they are already leading causes of disease in middle-income countries and of emerging importance in low-income countries (Ezzati and others 2004; WHO 2002). This chapter presents an evidenced-based review of the impact of high blood pressure, cholesterol, and bodyweight; the cost-effectiveness of relevant interventions; and the economic benefits of interventions. The chapter focuses on personal interventions—that is, those that are mediated largely by interpersonal actions and take place at the individual level. As such, the chapter should be considered as complementary to chapter 44 on lifestyles, which addresses populationwide interventions.
Prevention strategies have been broadly classified as individual based (also known as high risk) or population based (Rose 1985). The former typically involve screening to detect individuals above a certain threshold level of an individual risk factor—for example, people with hypertension—followed by personal interventions for those individuals. In contrast, the population-based approach aims at lowering mean risk-factor levels and shifting the population distribution of exposure in a favorable direction (Rose 1985). One example would be by reducing salt content in manufactured foods, thereby lowering blood pressure levels on a populationwide basis. Such an approach has the potential to produce large and lasting changes in disease incidence but requires substantial sociopolitical investments. Another approach is an evolution of the individual-based strategy in which treatments are targeted to those at high absolute risk of cardiovascular disease (CVD) rather than those with single risk-factor levels above traditional thresholds, such as hypertension or obesity (Jackson and others 1993). Such an approach appears to be highly cost-effective, with the potential to substantially reduce CVD rates when combined with populationwide interventions (Murray and others 2003).
